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Old 09-10-2011
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DNA frameshift mutation in cystic fibrosis

Hi all:

There is a question in UW concerning frameshift mutation in cystic fibrosis. It lists the normal sibling mRNA bp is 126bp, and the patient is 124bp. From this point, how do we know this is frameshift mutation, not codon deletion?

Thank you, sorry i did not frame the entire question, but i am sure a lot of people here did that question.
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Old 09-10-2011
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Codon deletion is in-frame deletion leading to shortening of protein expressed.

Frame-shift mutation is any mutation without it being a 3 or multiple of 3-AA deletion.
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Old 09-10-2011
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Frame shift is addition or deletion of 2 or multiple of 2 bases .
question says brother is 126 and pte is 124. As you can see 2 bases where deleted.

If question will say brother is 126 and pte 123 here I will go with in frame. Wich is addition or deletion of 3 or multiple of 3 bases.


Got it?????/

Last edited by evavar; 09-10-2011 at 10:01 AM.
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Old 09-10-2011
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thank you for reply, but I guess you want to say in frame mutation is addition or deletion of 3 or multiple of 3 bases?
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Old 08-23-2012
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bump...I thought CF was due to deletion that results in loss of phenylalanine at position 508? or is it due to frameshift? i'm confused.
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Old 08-24-2012
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Quote:
Originally Posted by warfarin90 View Post
bump...I thought CF was due to deletion that results in loss of phenylalanine at position 508? or is it due to frameshift? i'm confused.
U are right , cf is due to deletion of 3 basepairs leading to loss of phe . thats the cause in majority of cases. but in few cases frameshift mutations are the cause..
as far as this ques , i think its testing on recognising a frameshift mutation from the mrna samples, and not diagnosing cf based on these mutations..
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Old 08-24-2012
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Quote:
Originally Posted by chienpolska View Post
Hi all:

There is a question in UW concerning frameshift mutation in cystic fibrosis. It lists the normal sibling mRNA bp is 126bp, and the patient is 124bp. From this point, how do we know this is frameshift mutation, not codon deletion?

Thank you, sorry i did not frame the entire question, but i am sure a lot of people here did that question.
If it is codon deletion, the difference of sequence of mRNA between normal pp and patient should be 3 or multiples of 3. In this case, it is only 2 nucleotides difference, so it's from frameshift mutation.
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